1989 -

1975 -

In the 19th century the territory that was to become the states of Rwanda and Burundi fell under the colonial control of first Germany and then Belgium. The people that populated these areas were linguistically and culturally homogenous, but were still separated into three groups; the Hutu, the Tutsi and the Twa. The Hutu and the Tutsi were to some extent different in physical appearance, but the prevalent societal order was more one of social class than race, allowing Hutus to become Tutsis through social advancement. The German and -primarily- the Belgian colonialists capitalised on these existing societal divides, in essence exacerbating them through supporting centralised Tutsi rule as the means of colonial administration. Just as in Rwanda the Hutu group in Burundi constituted the majority of the population (approximately 85-90%), whilst the Tutsi were in a minority (approximately 10-14%). However, whilst the Hutu seized power in Rwanda at independence, power in Burundi became dominated by the Tutsi minority.

Burundi reached independence in 1962 and became a monarchy under the Tutsi king Mwami Mwambutsa IV. Power in the state was linked to Uprona (Union pour le Progrés National, Union for National Progress), a party connected to the Tutsi monarchy. Tutsi predominance within the state apparatus was violently challenged in an intrastate conflict in 1965 by a Hutu military rebellion which was quashed by the regime. Harsh retaliation from the army against the Hutu population and a cleansing of the army followed. In 1966 the monarchy was abolished by a coup and a military regime was imposed by the Tutsi-dominated army. Military regimes subsequently held power from 1966 to 1993 with dictators violently suppressing dissent, most notably in large-scale massacres of Hutus throughout the 1970s and 1980s. The military regimes attempted to maintain the structure of power and privilege in Burundi and all through their reign almost all positions of importance were held by the Tutsi minority. Also, in order to suppress ethnically based dissent the Tutsi regimes denied the existence of separate ethnic groups in Burundi, making the entire subject taboo.

In 1990 Burundi embarked on a process of democratisation. As political liberalisation began an intrastate conflict erupted, with the Palipehutu (Parti pour la libération du peuple Hutu, Party for the Liberation of the Hutu People) challenging the government in 1991 and 1992. The democratisation process culminated in elections in 1993, and Melchior Ndadaye -a Hutu- of the Frodebu (Front democratique de Burundi, Burundian Democratic Front) became president. Only months after his victory he was killed by members of the Tutsi-dominated army and violence quickly engulfed the country. Thousands of Tutsi were killed by Frodebu activists, whilst the army retaliated with equal force against Hutus. An Uprona and Frodebu power-sharing government failed to settle the crisis and in 1994 the conflict reignited, pitting the Tutsi-dominated government against a number of Hutu-based opposition groups, most notably the CNDD (Conseil national pour la défense de la démocratie, National Council for the Defence of Democracy) and the Palipehutu-FNL (Parti pour la liberation du peuple Hutu-Forces nationals de libération, Party for the Liberation of the Hutu People-Forces for National Liberation). In the context of this armed conflict several groups, including the government, made use of one-sided violence. Some rebel groups at times also battled each other.

The conflict raged between 1994 and 2008, when the last remaining rebel faction (of any notable size) agreed to enter the peace process. Most rebel groups had by the early 2000s entered into negotiations with the government and signed on to the Arusha process, which stipulated wide-ranging reforms of the army and society and a return to democracy through elections. Elections in 2005 ushered in the CNDD-FDD's Nkúrunziza as president of a government based on ethnic power sharing, and efforts to reign in the last remnant Hutu rebels continued.

Since 1946 Burundi has experienced the intrastate, non-state and one-sided categories of UCDP organised violence.